A major U.S. government report on the Keystone XL pipeline was written by oil industry consultants, say activist groups. The report, which was commissioned by the State Department and published two weeks ago, downplays the environmental impact of the pipeline and has been seen as key to potential approval.

The Keystone XL pipeline is a 1,661-mile-long oil project operated by TransCanada that will carry 830,000 barrels of crude oil a day from Alberta in Canada to refineries on the Texas Gulf Coast. The final decision on whether or not it can be completed lies with President Barack Obama. His decision is widely viewed as the ultimate litmus test of his environmental credentials.

“By hiring ERM, the State Department ignored its own guidelines and invited the fox into the hen house”, said Ross Hammond, Friends of the Earth senior campaigner. “The process that allowed them to get this contract has been corrupt from day one and the American people deserve better from their government.”

The ERM report – which runs to 11 volumes - argues that Keystone XL would not “significantly exacerbate” the problem of greenhouse gas emissions because in the event that the pipeline is not built, the crude can be sent by rail to Texas. It does concede that the crude (which is called tar sands by activists and oil sands by industry) will produce 17 percent more greenhouse gas emissions than conventional oil.

The oil industry is very pleased with the ERM report. “After five years and five environmental reviews, time and time again the Department of State analysis has shown that the pipeline is safe for the environment,” Cindy Schild, the senior manager of refining and oil sands programs at the American Petroleum Institute, told the New York Times.